image

Liquid ammonia - a highly concentrated nitrogen fertilizer containing 82% of the active substance of nitrogen, is readily soluble in water. Under normal conditions (0°C and 760 mm Hg) is a colorless gas with a sharp characteristic odor. At a temperature of -33.5°C and an atmospheric pressure of 760 mm, it condenses into a colorless liquid with a boiling point of -33.4°C. Liquid ammonia stored, transported and injection in liquefied form, so it is contained in vessels (tanks, cylinders) that withstand a minimum pressure of 20-30 atm. In tanks, ammonia is in the equilibrium state of the liquid and gaseous phase.

Ammonia is injected into the soil and the irrigation current of the water of the closed irrigation system in the form of a gas-liquid mixture, which is formed because of a different pressure drop on the way from the tank to the working irrigation pipeline. When it is injected into soil with high humidity (over 85% HB), the soil and plant residues sticks on the working elements, resulting in the furrow becoming wide, which leads to large losses of fertilizer. Liquid ammonia is introduced with simultaneous embedding it into the depth: on light soils 15-17 cm, heavy 12-14 cm; with irrigation water - in the form of an aqueous solution with a concentration of 0.01 to 0.0033%.

The rate and degree of absorption of ammonia by the soil depends on the content of humus, mechanical composition and humidity in it. On well-humified soils, normally treated and moistened, it is absorbed better than on light, humus-poor soils. The application on a leveled, well-grounded soil guarantees minimal losses and the greatest efficiency of liquid ammonia. Large losses occur when applied to dry clay soil. When the upper layer of the soil dries up and its humidity drops below 70% HB, it is better not to use ammonia, since it will not be fixed by the soil, which will lead to its large losses. The acidifying effect of ammonia is the same as that of ammonium nitrate. Ammonia promotes mineralization of organic matter and mobilization of soil nitrogen, phosphorus and potassium reserves, but it should be noted that these processes are limited by the zone of distribution of ammonia along the soil profile and its presence in in the soil free. Therefore, the calculated dose of phosphorus-potassium fertilizer should not be reduced.

After the injection of ammonia into the soil at the place of its action, the vital activity of the soil micro-flora may be temporarily disrupted, but after 7-10 days, the quantity of microorganisms is restored and then several times exceeds the initial level. Experience in the use of liquid ammonia in territory of Russian Federation shows its high efficiency for all crops, and in some areas ammonia is equivalent in its effects to ammonium nitrate. The rate of its application depends on the cultivated crop and the soil and climatic conditions of the micro zone. When using ammonia on irrigated land, it is necessary to focus on the rate of nitrogen in carrying it out by harvest; in dry conditions, it is necessary to make it 20-30% above the norm, since its loss from the soil is noted. Ammonia can be added as a main or additional fertilizer. To reduce losses of ammonia from the soil, it is recommended that all subsequent work on tillage will be done not earlier than a day after its injection. When applying liquid ammonia for pre-sowing cultivation, in order to avoid a negative effect on the germination of seeds, the sowing should be carried out no earlier than 10-12 hours after application. When applying with irrigation water on crops of continuous sowing, it is better to apply it in the first two watering, until the soil is heavily compacted and has good infiltration.

When growing tilled crops effectively as a pre sowing application of ammonia with pre-sowing irrigation, and during the growing season, but necessarily after inter-row processing. The use of ammonia with irrigation water significantly reduces nitrogen losses, which will be determined by the intensity of evaporation of irrigation water. Therefore, it is best to produce additional watering in the morning and evening hours with a minimum deficit of air humidity.

Ammonia introduced into the soil at a temperature of 20-25°C and soil moisture content 75-80% HB is subjected to a nitrification process, as a result of which ammonia nitrogen passes into nitrates. Nitrate nitrogen has greater mobility and under irrigation conditions, it is easily washed out of the active layer of the soil, which leads to unproductive nitrogen losses. In droughty years, nitrates with an ascending current of water move to the soil surface and accumulate in the uppermost layer of it, which can lead to the accumulation of a toxic amount of nitrates in agricultural products and water sources. To reduce nitrogen losses of fertilizers and to limit the danger of accumulation of toxic amounts of nitrates in agricultural products, inhibitors of the nitrification process should be used. Within 4-6 weeks, the nitrification of ammonium forms of fertilizers is suppressed by the derivatives of pyridine and pyrimidine. Inhibitors are mixed with ammonia before application. The dose of the inhibitor, varying depending on the amount of active ingredient, the timing of application, the sowing culture, should be 0.25-2% of the dose of introduced nitrogen.

• • • • • • •

The article was prepared using educational and methodical literatureof famous Russian technique and agricultural specialists and Scientific’s for the period 1984-2017 years.